According to later Greek writers, Mytilene was founded in the 11th century BC by the family Penthilidae, who arrived from Thessaly, and ruled the city-state until a popular revolt (590–580 BC) led by Pittacus of Mytilene ended their rule. In fact the archaeological and linguistic record may indicate a late Iron Age arrival of Greek settlers although references in Late Bronze Age Hittite archives indicate a likely Greek presence then. The name Mytilene itself seems to be of Hittite origin. According to Homer's Iliad, Lesbos was part of the kingdom of Priam, which was based in Anatolia (present day Turkey). Much work remains to be done to determine just what happened and when. In the Middle Ages, it was under Byzantine and then Genoese rule. Lesbos was conquered by the Ottoman Empire in 1462. The Ottomans then ruled the island until the First Balkan War in 1912, when it became part of the Kingdom of Greece.

According to Classical Greek mythology, Lesbos was the patron god of the island. Macar was reputedly the first king whose many daughters bequeathed their names to some of the present larger towns. In Classical myth his sister, Canace, was killed to have him made king. The place names with female origins are claimed by some to be much earlier settlements named after local goddesses, who were replaced by gods, however there is little evidence to support this.[citation needed]Homer refers to the island as "Macaros edos", the seat of Macar. Hittite records from the Late Bronze Age name the island Lazpa and must have considered its population significant enough to allow the Hittites to "borrow their gods" (presumably idols) to cure their king when the local gods were not forthcoming. It is believed that emigrants from mainland Greece, mainly from Thessaly, entered the island in the Late Bronze Age and bequeathed it with the Aeolic dialect of the Greek language, whose written form survives in the poems of Sappho, amongst others.

During the Middle Ages it belonged to the Byzantine Empire. In 802, the Byzantine Empress Irene was exiled to Lesbos after her deposition, and died there.[4] The island served as a gathering base for the fleet of the rebel Thomas the Slav in the early 820s.[4]

In the 10th century, it was part of the theme of the Aegean Sea, while in the late 11th century it formed a dioikesis under a kourator in Mytilene.[4] In the 1090s, the island was briefly occupied by the Turkish emir Tzachas, but he was unable to capture Methymna, which resisted throughout.[4] In the 12th century, the island became a frequent target for plundering raids by the Republic of Venice.[4]

The cities of Mytilene and Methymna have been bishoprics since the 5th century. By the early 10th century, Mytilene had been raised to the status of a metropolitan see. Methymna achieved the same by the 12th century.[4]

The oldest artifacts found on the island may date to the late Paleolithic period.[5] Important archaeological sites on the island are the Neolithic cave of Kagiani, probably a refuge for shepherds, the Neolithic settlement of Chalakies, and the extensive habitation of Thermi (3000–1000 BC). The largest habitation is found in Lisvori (2800–1900 BC) part of which is submerged in shallow coastal waters. There are also several archaic, classical Greek and Roman remains. Vitruvius called the ancient city of Mytilene "magnificent and of good taste". Remnants of its medieval history are three impressive castles.

Lesbos is the birthplace of several famous people. In archaic times, Arion developed the type of poem called dithyramb, the progenitor of tragedy, and Terpander invented the seven note musical scale for the lyre. Two of the nine lyric poets in the Ancient Greek canon, Alcaeus and Sappho, were from Lesbos. Phanias wrote history. The seminal artistic creativity of those times brings to mind the myth of Orpheus to whom Apollo gave a lyre and the Muses taught to play and sing. When Orpheus incurred the wrath of the god Dionysus he was dismembered by the Maenads and of his body parts his head and his lyre found their way to Lesbos where they have "remained" ever since. Pittacus was one of the Seven Sages of Greece. In classical times Hellanicus advanced historiography, Theophrastus, the father of botany, succeeded Aristotle as the head of the Lyceum. Aristotle and Epicurus lived there for some time, and it is there that Aristotle began systematic zoological investigations[6]. In later times lived Theophanes, the historian of Pompey's campaigns, Longus wrote the famous novel Daphnis and Chloe, and much later the historian Doukas wrote the history of the early Ottoman Turks. In modern times the poet Odysseus Elytis, descendant of an old family of Lesbos received the Nobel Prize.

Twelve historic churches on the island were listed together on the 2008 World Monuments Fund's Watch List of the 100 Most Endangered Sites in the world. The churches range in date from the Early Christian Period to the 19th century. Exposure to the elements, outmoded conservation methods, and increased tourism are all threats to the structures. The following are the 12 churches:[8]

Lesbos lies in the far east of the Aegean sea, facing the Turkish coast (Gulf of Edremit) from the north and east; at the narrowest point, the strait is about 5.5 km (3.4 mi) wide. The shape of the island is roughly triangular, but it is deeply intruded by the gulfs of Kalloni, with an entry on the southern coast, and of Gera, in the southeast.[9]

The island is forested and mountainous with two large peaks, Mt. Lepetymnos at 968 m (3,176 ft) and Mt. Olympus at 967 m (3,173 ft), dominating its northern and central sections.[10] The island's volcanic origin is manifested in several hot springs and the two gulfs.

Lesbos is verdant, aptly named Emerald Island, with a greater variety of flora than expected for the island's size. Eleven million olive trees cover 40% of the island together with other fruit trees. Forests of mediterranean pines, chestnut trees and some oaks occupy 20%, and the remainder is scrub, grassland or urban.

Lesbos is a separate regional unit of the North Aegean region, and the only municipality of the regional unit. As a part of the 2011 Kallikratis government reform, the regional unit Lesbos was created out of part of the former Lesbos Prefecture. At the same reform, the current municipality of Lesbos was created out of the 13 former municipalities on the island:[14]

In English and most other European languages including Greek, the term lesbian is commonly used to refer to homosexual women. This use of the term derives from the poems of Sappho, who was born in Lesbos and who wrote with powerful emotional content directed toward other women.[15] Due to this association, Lesbos and especially the town of Eresos, her birthplace, are visited frequently by LGBT tourists.[16]

The "gay" connotation of the term is considered offensive to many Lesbos islanders to such a degree that, in 2008, a group of Lesbos islanders litigated unsuccessfully a court case against the LGBT community of Greece. The islander group had requested a legal injunction to ban groups from using the word lesbian in their names, which the petitioners claim violated their human rights as it is "insulting" and disgraces them around the world.[17][18]